(1) Field of the Invention
The invention relates to a fire resistant aluminum door frame assembly whereby upon exposure to extreme heat, the door frame assembly accommodates expansion of header and jamb assemblies without buckling and strike and hinge assemblies respectively maintain door support and lockset engagement of a door member wherein said door frame assembly attains a fire rating.
(2) Description of the Prior Art
Present day partition wall construction utilizes many door framing constructions. It is preferable that a metal door frame be utilized since the use of wooden framing has become too costly and also diminishes the fire resistancy of the entire partition wall construction. The problem with utilization of metal members is that the thermal coefficient of expansion is much greater than when wooden members are used. Upon exposure to extreme heat, metal members tend to expand and buckle. If the buckling is not retarded, gaps along the door and door frame occur and thus provide avenues of passage for heat, smoke and combustion. It has thus become a concern of the industry to solve this problem. An additional problem has ensued with regard to the use of aluminum door framing. Aluminum members are highly desirable due to their light weight and attractive appearance. Additionally, the ease of extruding aluminum members makes them even more desirable. At elevated temperatures, aluminum tends to soften and door support can be lost in addition to the harmful side effects of buckling. Aluminum jamb members are generally about twice the length of header members and thus the linear expansion of these members must be accommodated much more than the concomitant expansion of header members. Generally, few fire rated aluminum door frame systems are extant in the prior art, and those that are involve the utilization of unconventional studs for accommodation of particularly formed jamb and header members for utilization therewith. It would be desirable to utilize conventional wood or steel stud members such that the cost of the door frame would not thereby be increased. Additionally, previous encounters with this problem have sought to include cap members extending across the top of the door opening with a slideable facia plate which can slide past upper portions of the jamb assemblies. Such solutions, however, prohibit attaining expansion accommodation of the jamb assemblies which must be accomodated in conjunction with this header expansion. Additionally this past utilization of aluminum door framing does envision reversibility of jamb members such that a left hand or right hand swinging door can be accommodated within a door opening and partition wall construction. Also, numerous frames require many elements which increase the cost of the frame. It would be desirable to reduce the number of frame members when using aluminum elements and still provide continuous door support upon exposure to extreme heat.
In conjunction with the problems noted in the prior art, it is additionally an esthetic concern to provide a strike assembly which comprises aluminum and creates the pleasing appearance of a continuous aluminum set of elements.
(3) Objects of the Invention
Accordingly, it is a primary object of the invention to provide an aluminum door frame for use with partition wall construction which accommodates expansion of header and jamb members upon exposure to extreme heat.
It is an allied goal of the invention to provide such an aluminum door frame for use with conventional stud means and eliminate the need for specifically shaped mating stud members for use with header and jamb assemblies.
It is an important object of the invention to additionally maintain door support upon exposure to heat.
It is a concomitant object of the invention to provide a strike assembly comprising aluminum to afford a continuous aluminum esthetically pleasing appearance.
Another object of the invention is to reduce the number of components in an aluminum door frame assembly which still provides fire resistancy.
A related goal of the invention is to provide an aluminum door frame assembly which facilitates ease of installation by conventional screw attachment.